SOLUTION: how do i decide all values of b in the following equations that will give one or more real number solutions? If an equation has solution how do i write a rule for judging by lookin

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Question 79119: how do i decide all values of b in the following equations that will give one or more real number solutions? If an equation has solution how do i write a rule for judging by looking at it in standard form?
a. 3x^2+bx-3=0
b. 5x^2+bx+1=0
c. -3x^2+bx-3=0
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
how do i decide all values of b in the following equations that will give one or more real number solutions? If an equation has solution how do i write a rule for judging by looking at it in standard form?
a. 3x^2+bx-3=0
b. 5x^2+bx+1=0
c. -3x^2+bx-3=0
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Rule:
b^2-4ac must be >=0
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a. b^2-4*3*-3>=0
b^2>=-36
b can be any Real Number Value
.------------------------------------
b. b^2-4*5*3>=0
b^2>=60
b>=2sqrt15 or b<=-2sqrt15
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c. b^2-4*-3*-3>=0
b^2>=36
b>=6 or b<=-6
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Cheers,
Stan H.